AV Police Squad


“What’s the login information for that mixer?”


“Where does cable A3074 connect to?”


“Just update the projector module. Do you have the program?”


“What’s the IP address of those processors?”


You know what I’m talking about: Documents On Hand, or DOH. (I bet you thought those were just Homer Simpson references. Silly!) These are the documents that should be left with the system so that any technician or operator that has to interact with the system will have access to them.

In the days of yore, it used to be enough to laminate some system drawings and stick them to the side of the rack. Those days are long gone. With the adoption of DSP processors, system drawings just show how devices are connected. There is no way to understand the signal flow. They are simply wire maps and do not provide enough information to service the system.

So, what should be included in the DOH?

At the bare minimum:

  • AV Drawings: Although they don’t contain as large a share of system information as they used to, they are still critical documents and should live with the system. Plus, with free notation apps, pdfs or CAD drawings can be redlined digitally and distributed over the interwebs for formal updates.
  • IP Addresses with Login Information: There are many ways to get an IP address without having a nice sheet handy, but it is just so much easier to look it up than it is to break out WireShark or an RS232 cable (remember those?!). On the other hand, without login information, there may be no way to access the devices, unless all the default credentials were left unchanged.  While this may sound appealing for its simplicity, in today’s network security conscious world, it is a huge no-no.
  • Audio Site Files: Sure you can simply pull them off most mixers, but what if you need to replace a failed unit? It is vital to have backup copies of the mixer configurations.
  • Control System Files: If a device module needs to be changed or the client logo was just updated, it is so much easier to simply walk a tech through these simple updates over the phone without requiring an engineer/programmer in the field.
  • Operating Manual: System users may change more than a newborn’s diaper, especially in higher education. They need to know how to work the system. Having the operating manual on hand is not only tremendously helpful for the users (both old and new), but also for service technicians who may not be familiar with the operation of the system. We like to think that our control systems are completely intuitive to use, but I’ve seen some doozies out there.

Ideally, the DOH remains on some editable media in the vicinity of the system. This could be a USB stick in the back of the rack or a Raspberry Pi server sitting on a shelf. The idea is that all these documents remain accessible to people that need them, regardless of cell service, network access or computer OS. This also allows any updates to be made immediately and kept with the system as a backup. Remember the old Marine Corp adage: “Two is one, one is none.” It holds as true for cutting implements in the bush as it does for saved copies of files. Any work should be saved twice, once on your computer and once on the DOH medium.

Creating a complete DOH suite left with the system will hopefully avoid actual “d’oh” moments.


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